Radioactive Iodine Treatment (RAI)

RAI Part 2

If you are advised to have radioactive iodine therapy, this will need to be as an inpatient in a special cubicle known as an isotope or isolation room.

This room is specially adapted because of the high dose of radiation involved in treatment. Unlike a normal hospital ward you will not be allowed to have visitors in the room. Adult visitors (provided they are not pregnant) can visit but must stay in a designated area outside the room.

You can talk to each other either through a protective window or possibly by using a phone link. You cannot have children to visit.

The treatment dose of radioactive iodine is usually given as a capsule to swallow. The capsule is a similar size to a paracetamol capsule.

Many patients do not experience any side effects with radioactive iodine. However the following side effects can occur:

dry mouth

tender or swollen saliva glands

taste changes

sore throat

altered sensations around your thyroidectomy scar

swelling in the thyroid area if a significant amount of thyroid tissue is still present

feeling sick (although this is uncommon)

You will be asked if you are pregnant before the radioactive iodine capsule is given to you. If there is any doubt then a pregnancy test will be done as the treatment cannot go ahead if you are pregnant.

After the radioactive iodine dose has been given to you, you will need to avoid becoming pregnant for 6 months or avoid fathering a child for 4 months.

Following Radioactive Iodine Treatment

The treatment will make you radioactive for a period of time afterwards and therefore you will need to stay in the isolation room whilst the levels of radiation are very high. The levels of radiation will be monitored whilst you are in the room and once the readings have fallen enough (often after 3-4 days) you will be allowed to go home.

You will have a full body scan using a gamma camera (see www.goingfora.com/radiology) after the treatment and this is done to see where the radioiodine has gone in the body.

If you were not already on thyroxine before your treatment this needs to be started and you are likely to be given a prescription to go home with.

You will still be radioactive when you go home therefore you will still need to be careful and follow some guidelines (radiation protection measures) in order to reduce the risks to those people around you.

Here are some examples of what to expect when you go home:

sleep alone

try to keep more than 6 feet away from other people wherever possible

avoid prolonged close contact with adults and particularly pregnant women and children

avoid using public transport and going to the cinema/theatre, i.e, places where you may be seated next to the same person for prolonged periods

flush the toilet twice

avoid becoming pregnant for 6 months or fathering a child for 4 months

The length of time that you will need to follow the guidance varies between patients but your hospital will give you precise instructions and the date on which you can mix with adults normally and another date for when you can mix with children and pregnant or potentially women.

If you are planning to travel by ferry or plane shortly after your treatment then it may be advisable to carry a letter stating that you have recently received radioactive treatment. This is to avoid any confusion that may be caused by sensitive radiation recording devices at airports and ferry terminals.

Other Radioactive Treatments

Some patients with medullary thyroid cancer may be suitable for radioactive treatment using different types of radioactive chemical. An example is mIBG (metaiodobenzylguanidine) treatment.

Although mIBG also uses radioactive iodine it is very different to the treatment explained above. This treatment is given in the isolation room but needs to be given through a drip into the bloodstream rather than as a capsule to swallow.

It is important to monitor blood pressure readings during this type of treatment and to give anti-sickness medicine before the treatment starts.

It is likely that the stay in the isolation room will be between 5 and 7 days and again a full body scan using a gamma camera will be done afterwards to see where the chemicals have gone in the body. There is no need to stop thyroid hormones before this type of treatment. However some other medications may need to be changed or stopped before mIBG treatment and your hospital team will advise you on this issue.